LINE-1 methylation status of endogenous DNA double-strand breaks

DNA methylation and the repair of DNA double-strand breaks (DSBs) are important processes for maintaining genomic integrity. Although DSBs can be produced by numerous agents, they also occur spontaneously as endogenous DSBs (EDSBs). In this study, we evaluated the methylation status of EDSBs to determine if there is a connection between DNA methylation and EDSBs. We utilized interspersed repetitive sequence polymerase chain reaction (PCR), ligation-mediated PCR and combined bisulfite restriction analysis to examine the extent of EDSBs and methylation at long interspersed nuclear element-1 (LINE-1) sequences nearby EDSBs. We tested normal white blood cells and several cell lines derived from epithelial cancers and leukemias. Significant levels of EDSBs were detectable in all cell types. EDSBs were also found in both replicating and non-replicating cells. We found that EDSBs contain higher levels of methylation than the cellular genome. This hypermethylation is replication independent and the methylation was present in the genome at the location prior to the DNA DSB. The differences in methylation levels between EDSBs and the rest of the genome suggests that EDSBs are differentially processed, by production, end-modification, or repair, depending on the DNA methylation status.     

Trends in obesity and associations with education and urban or rural residence in Thailand

Objective: To measure trends in the prevalence of overweight and obesity and the relationship with urban or rural residence and education in Thailand. Research Methods and Procedures: Data were from two nationally representative surveys of 38,323 individuals ≥18 years old (19,156 were 18 to 59 years old) in 2004 and 3375 individuals 18 to 59 years old in 1997. Overweight and obesity were defined using the World Health Organization's Asian criteria. Results: Among those ≥18 years old in 2004, 17.8% of men (95% confidence interval, 16.6% to 19.0%) were overweight, 18.4% (17.3% to 19.5%) had Class I obesity, 4.8% (4.1% to 5.5%) had Class II obesity, and 15.9% (14.6% to 17.1%) had abdominal obesity. In women, 18.2% (17.1% to 19.2%) were overweight, 26.1% (24.9% to 27.3%) had Class I obesity, 9.3% (8.6% to 10.0%) had Class II obesity, and 37.3% (35.3% to 39.2%) had abdominal obesity. In those 18 to 59 years old, the prevalence of Class I obesity in men and all four categories in women significantly increased between 1997 and 2004. There was an inverse relationship in women but a positive relationship in men between education and the odds of being overweight or obese. In 2004, there were significantly lower odds of being overweight or obese in rural compared with urban men but similar odds between urban and rural women. Discussion: The prevalence of overweight and obesity in Thailand is high and increasing. Although the transition of overweight and obesity to those of lower socioeconomic status is not complete, it is well on the way.     

Gender Differences in Health Expectancies across the Disablement Process among Older Thais

Objectives

To estimate health expectancies based on measures that more fully cover the stages in the disablement process for the older Thais and examine gender differences in these health expectancies.

Methods

Health expectancies by genders using Sullivan’s method were computed from the fourth Thai National Health Examination Survey conducted in 2009. A total of 9,210 participants aged 60 years and older were included in the analysis. Health measures included chronic diseases; cognitive impairment; depression; disability in instrumental activities of daily living (IADL); and disability in activities of daily living (ADL).

Results

The average number of years lived with and without morbidity and disability as measured by multiple dimensions of health varied and gender differences were not consistent across measures. At age 60, males could expect to live the most years on average free of depression (18.6 years) and ADL disability (18.6 years) and the least years free of chronic diseases (9.1 years). Females, on the contrary, could expect to live the most years free of ADL disability (21.7 years) and the least years free of IADL disability (8.1 years), and they consistently spent more years with all forms of morbidity and disability. Finally, and for both genders, years lived with cognitive impairment, depression and ADL disability were almost constant with increasing age.

Conclusion

This study adds knowledge of gender differences in healthy life expectancy in the older Thai population using a wider spectrum of health which provides useful information to diverse policy audiences.     

Molecular properties of membrane-bound FAD-containing D-sorbitol dehydrogenase from thermotolerant Gluconobacter frateurii isolated from Thailand

There are two types of membrane-bound D-sorbitol dehydrogenase (SLDH) reported: PQQ-SLDH, having pyrroloquinoline quinone (PQQ), and FAD-SLDH, containing FAD and heme c as the prosthetic groups. FAD-SLDH was purified and characterized from the PQQ-SLDH mutant strain of a thermotolerant Gluconobacter frateurii, having molecular mass of 61.5 kDa, 52 kDa, and 22 kDa. The enzyme properties were quite similar to those of the enzyme from mesophilic G. oxydans IFO 3254. This enzyme was shown to be inducible by D-sorbitol, but not PQQ-SLDH. The oxidation product of FAD-SLDH from D-sorbitol was identified as L-sorbose. The cloned gene of FAD-SLDH had three open reading frames (sldSLC) corresponding to the small, the large, and cytochrome c subunits of FAD-SLDH respectively. The deduced amino acid sequences showed high identity to those from G. oxydans IFO 3254: SldL showed to other FAD-enzymes, and SldC having three heme c binding motives to cytochrome c subunits of other membrane-bound dehydrogenases.     

Delayed Plasmodium falciparum clearance following artesunate-mefloquine combination therapy in Thailand, 1997-2007

ABSTRACT: BACKGROUND: There is concern that artesunate resistance is developing in Southeast Asia. The purpose of this study is to investigate the prevalence of parasitaemia in the few days following treatment with artesunate-mefloquine (AM), which is an indirect measure of decreased artesunate susceptibility. METHODS: This is a retrospective analysis of 31 therapeutic efficacy studies involving 1,327 patients treated with AM conducted by the Thai National Malaria Control Programme from 1997- 2007. RESULTS: The prevalence of patients with parasitaemia on day 2 was higher in the east compared to the west (east: 20 %, west: 9 %, OR 2.47, 95 % CI: 1.77, 3.45). In addition, the prevalence of day-2 parasitaemia increased over time (OR for each year = 1.10, 95 % CI: 1.03, 1.19). After controlling for initial parasitaemia and age, year and region remained important determinants of day-2 parasitaemia (OR for region = 3.98, 95%CI 2.63, 6.00; OR for year = 1.28, 95%CI: 1.17, 1.39). The presence of parasitaemia on day 2 and day 3 were specific, but not sensitive predictors of treatment failure. DISCUSSION: Delayed resolution of parasitaemia after AM treatment increased in eastern Thailand between 1997 and 2007, which may be an early manifestation of decreased artesunate susceptibility. However, clinical and parasitological treatment failure after 28 days is not changing over time (which is related to both mefloquine and artesunate decreased susceptibility). The presence of parasitaemia on day 2 is a poor indicator of AM 28-day treatment failure.     

Facile synthesis and anticancer activity of C-10 non-acetal deoxoartemisinin dimers

In this research, N-(2-aminoethyl)glycine-linked C-10 non-acetal deoxoartemisinin dimers were synthesized by using solution phase peptide synthesis approach. In addition, chemical modification of the C-10 non-acetal deoxoartemisinin monomers and dimers by adding a lysine unit to the N-terminus has been performed. The biological activities of all synthesized compounds were evaluated against the colon cancer cell line (Caco-2). The non-acetal deoxoartemisinin monomers 12a, 15a–c and dimers 13a, 16a–c were active against Caco-2 cells and more potent than dihydroartemisinin.     

Sows exposed to octylphenol in early gestation: No estrogenic effects in male piglets, but increased rate of stillbirth

Octylphenol is an industrial chemical with estrogenic effects both in vitro and in vivo. In this study the effects of short-term intramuscular exposure to 0.1 mg/kg of body weight and 1.0 mg/kg of body weight in early gestation were evaluated in pregnant sows with respect to reproductive parameters in the newborn male piglets, as compared with male piglets from unexposed control sows. The male piglets were examined immediately after birth with respect to the macroscopic appearance of the reproductive organs and testosterone concentration in serum. It was not possible to identify any estrogenic effects in the newborn male piglets. However, in the sows exposed at the highest level of octylphenol, there was an increased number of stillborn piglets and an increased proportion of sows with stillborn piglets in the litter (P < 0.05). This was an unexpected finding which has not been reported previously.     

Human papillomavirus genotypes among infected Thai women with different cytological findings by analysis of E1 genes

Cervical cytological data may not be sufficient for cervical cancer screening and prevention. In this project, we determined HPV genotype among infected Thai women with different cytological findings by characterization of E1 genes. Five hundred and thirty-five specimens were tested by PCR amplification of the E1 genes. HPV genotypes were determined by sequencing, comparison with the GenBank database and were analyzed in relation to different cytological findings. HPV-DNA by PCR were typed and revealed 32 different genotypes. HR-HPV (HPV16, 18 or 52) was detected in all samples with cervical cancer cytology. HPV16 was most prevalent irrespective of cervical cytology. Moreover, HPV31 and 52 were most prevalent in the HSIL and LSIL groups whereas HPV66 was found mostly in the LSIL group. The LSIL group displayed the highest variation of HPV genotypes. Moreover, HPV31 and 52 predominated in the HSIL and LSIL groups especially HPV52 which was found in cancer samples. We hoped that these data of HPV genotypes can be used as preliminary data of HPV in Thailand and can serve as basic data for future research into the HPV genotype in south-east Asia.     

Increased number of Arginine-based salt bridges contributes to the thermotolerance of thermotolerant acetic acid bacteria, Acetobacter tropicalis SKU1100

Constitution of oxidative defense systems and, correspondingly, oxidative stress prevention are highly dependent on amino acid supply. In vitro, experiments have demonstrated that amino acid availability participates to the homeostasis of reactive oxygen species. However the molecular mechanisms involved in the maintenance of redox homeostasis responsive to circulating amino acid levels remain unclear. As GCN2 is a protein kinase considered to be an important sensor for amino acids availability and a potential regulator of redox homeostasis, we hypothesized that this kinase can modulate redox homeostasis in vivo, in response to an amino acid-imbalanced diet.We investigated the response of GCN2+/+ and GCN2−/− mice to a long-term (24 weeks) leucine-imbalanced diet (EDΔLeu). In order to evaluate the oxidation level in each group of mice, we determined the degree of protein oxidation in the liver. Interestingly, GCN2−/− mice exhibited an increase in protein carbonylation, a marker of oxidative stress, in response to the EDΔLeu diet. These data correlate with a decrease in hepatic GPX1 expression, a major antioxidant enzyme, and a decrease in total GPX activity in the liver. Our results suggest that GCN2 and its downstream signaling pathway have an important role in the protection against oxidative injuries induced by an amino acid-imbalanced diet, and that it can play a critical role in the prevention of oxidative damage.     

Artemisinin resistance containment project in Thailand. II: responses to mefloquine-artesunate combination therapy among falciparum malaria patients in provinces bordering Cambodia

ABSTRACT: BACKGROUND: The area along the Thai-Cambodian border is considered an epicenter of anti-malarial drug resistance. Recently, parasite resistance to artemisinin-based therapies has been reported in the area. The artemisinin resistance containment project was initiated in November 2008, with the aim to limit resistant parasites and eliminate malaria in this region. This study describes the response to artemisinin-based therapy among falciparum malaria patients in the area, using data from the malaria surveillance programmed under the containment project. METHODS: The study was conducted in seven provinces of Thailand along the Thai-Cambodian border. Data of Plasmodium falciparum-positive patients during January 2009 to December 2011 were obtained from the electronic malaria information system (eMIS) Web-based reporting system. All P. falciparum cases were followed for 42 days, as the routine case follow-up protocol. The demographic characteristics of the patients were described. Statistical analysis was performed to determine the cure rate of the current standard anti-malarial drug regimen-- mefloquine-artesunate combination therapy (MAS). The proportion of patients who remained parasite-positive at each follow-up day was calculated. In addition, factors related to the delayed parasite clearance on day-3 post-treatment, were explored. RESULTS: A total of 1,709 P. falciparum-positive cases were reported during the study period. Almost 70% of falciparum cases received MAS therapy (n = 1,174). The majority of cases were males, aged between 31 and 50 years. The overall MAS cure rate was >90% over the threeyear period. Almost all patients were able to clear the parasite within 7 to 14 days posttreatment. Approximately 14% of patients undergoing MAS remained parasite-positive on day-3. Delayed parasite clearance was not significantly associated with patient gender, age, or citizenship. However, delayed parasite clearance varied across the study area. CONCLUSION: Anti-malarial drug-resistant parasites should be closely monitored in the area along the Thai- Cambodian border. Although the MAS cure rate in this study area was above 90%, an increasing trend of treatment failure has been reported in neighboring parts. Effective malaria surveillance is an important component to monitor drug-resistance in the malaria containment project.